President Obama is all about sound science and a fresh global image. On these points he has no better opportunity than building on the prior White House's $15 billion worldwide AIDS program, one of former President George W. Bush's notable successes.

But he fumbled the first step with summary firing of Dr. Mark Dybul, who was dismissed as global AIDS czar the day after Obama's swearing-in. It was unexpected, unceremonious and undeserved.

It's a president's prerogative to name his own team, and the Obama insiders and Dybul had agreed on a waiting period before a successor was lined up. But that orderly timetable was shredded after politics entered the picture.

Dybul, a gay physician who once worked in San Francisco, was scapegoated for the marginal portions of the Bush AIDS initiative such as an emphasis on sexual abstinence and a ban on aiding prostitutes. These stances, while objectionable, never stood at the heart of far-larger goals of prevention, research and medical treatment that has enrolled two million worldwide. But to critics, Dybul didn't object loudly enough and had to go, pronto, this instant, right now.

These are intemperate charges that miss the big picture: a conservative White House that woke up to a global scourge and actually did something. In noting Dybul's departure, the British public health journal Lancet described the effort as "the largest and most successful bilateral HIV/AIDS programme worldwide."

If the president isn't careful, the AIDS fight may return to the bad old days with factions fighting over the latest trend or more perfect answer. It's a special worry as Congress is asked to follow through on its vote last year to increase spending to $48 billion in future years, a pledge that looks iffy as economic conditions tighten.

Obama should mend his mistake by finding a replacement who matches Dybul's experience and competence. That task could be a challenge given shabby handling of this praiseworthy public official.